I just upgraded to Windows 7 Professional (clean install) from Windows Vista Ultimate. I have a hard wired connection (netgear DSL Rputer) to a Windows Vista Home Premium PC and can get from the Vista PC to the Windows 7, but not the other way. I had this same problem before I upgraded. I pinged both PCs by IP and name and verified all the info was correct. I have the same user name on both PCs. I made sure that under my network connection of IPv4 I have selected NETBIOS over TCP/IP. Network discovery is on for both PCs and file sharing is enabled. My windows 7 PC (in Windows Explorer) shows the Vista PC but I keep getting the same error. I have Bitdefender Total Security and have it configured properly for both PCs. Even with both firewalls disabled I get the same error message. I even tried setting the gateway address manually on the Vista PC but to no avail. When I had Windows XP on both PCs I had no problem networking so I don't believe it is hardware related. Once I upgraded to Vista the problem began. I reviewed your links about this problem and nothing seems to work. I don't know if I can use my original Vista Ultimate software to upgrade the Home Premium, but that could possibly solve the problem. To add to my problem above I tried a number of suggestions by tech forums. I checked the services and workstation, DHCP Client, DNS Client, LanmanServer, TCP/IP NetBIOS Helper and Computer Browser were all running. I tried uninstalling and reinstalling file and print sharing for Microsoft Networks. I then used regedit to check the LanmanServer permissions and everyone and system have full access. Nothing seems to work. The next step is to repair my Windows Vista installation, but I will wait for some other suggestions before I try. Well its been 10 days the Microsoft gurus can't solve my problem.